1. Technical Field
The present invention relates to an image processing device, an image processing method, and a printed material.
2. Related Art
Conventionally, almost all paper for wrapping goods and the like (hereinafter, referred to as wrapping medium) has been mass-produced by gravure printing with a small variety of product types. There has been demand for small-quantity production of a wrapping medium with a wide variety of product types in order to meet various needs of customers.
Printing by an ink-jet printer in which ink is discharged to a printing medium does not need plate making necessary for gravure printing, and enables small-quantity production with a wide variety of product types. Ink-jet printers can perform printing neatly without smearing or bleeding through by performing printing to special paper having a coating layer. However, since wrapping paper generally used in production of a wrapping medium by gravure printing has no coating layer, when such wrapping paper is used as a printing medium in an ink-jet printer, there are cases where the amount of ink is excessive, and smearing or bleeding through occurs. Thus, there has been a problem with printing by an ink-jet printer using conventional wrapping paper. Further, when the discharge amount of ink is decreased in an ink-jet printer to prevent smearing or bleeding through, there are cases where the color density will be decreased and the image quality will be deteriorated compared to the image quality of gravure printing.
A conventional image processing device is configured to determine a region where lightness is high and a region where is lightness is low in image data, and adjust the discharge amount of ink based on the determination results. Consequently, the amount of ink discharged to printing paper is decreased while unsharpness of a printed image is controlled (e.g., see Japanese Laid-Open Patent Publication No. 2008-271045).